The development of mobile communication networks involves today to a great extent not only basic services relating to the transmission of conventional calls but also options allowing higher transmission speed and entertainment solutions. For example solutions of a service-on-demand type become possible as the data transmission capacity increases. As regards fixed telephone and cable networks, known solutions include for instance the one disclosed in EP 01400593 for ordering music videos to the user's home. In the solution disclosed, especially intended for transmitting short-term services, the subscriber selects a video from a large number of music videos, sends an order for the item and begins to receive transmission for example in 30 seconds' time from the order. In this solution, the orders by different users are sent to the users irrespective of each other, i.e. to each user separately. Video-on-demand solutions used for transmitting long-term services, such as video films, have been implemented in fixed data transmission networks also in such a way that when the user knows that a particular video film is transmitted for example at 14 and 18 o'clock, he/she can register to watch the transmission beginning at 18. Hence, the same content is sent to several users, thus reducing the costs the users have to bear. Further, from the point of view of the service provider, it is possible in the above solution to wait until there are for example ten subscribers to the film, to inform the user when the required number of subscribers is fulfilled, and subsequently to start the transmission.
The fixed network solutions according to the prior art, in which the service begins at a given time or once there are a given number of subscribers, are not optimal what it comes to the convenience of use.